A picture would be helpful, one when cold, one when it is 1/2 way cleared, and one when the lines are gone. However, it is either the T-con, or the tabs on the LCD glass inside the panel, or the contact between the T-con and the panel. You can open up the set and remove the flat ribbon cables between the T-con board and the panel and clean them (with a pencil eraser) and re-seat them to see if it is going to be the easy fix. Otherwise it will likely be too costly to repair or even replace the panel. Good luck...